Splash-plate for stamp-mills.



No. 800,398. PATENTED SEPT. 26, 19.05.

H c. RICHARDS. SPLASH PLATE FOR STAMP MILLS.

APPLICATION FILED JULY 11, 1904.

WlltflZGS-S'GSI- L A Inventor UNITED STATES" PATENT OFFICE.

SPLASH-PLATE FOR STAMPeMlLLS.

Specification of Letters Patent.

' Patented Sept, 26, 1905.

Application filed July 11, 1904. Serial Na 216,034..

\ used in conjunction with stamp-mill mortars.

It is usual in stamp-mills to employ a mortar having one or more screen-openings, through which the pulverized ore and water are ejected by the action of the stamps, the

; constant lifting and dropping of the stamps causing a splashing in the mortar and the screens being disposed in the immediate range of the splash. Passing through the screens the ore and water impinge generally against ordinary plain surfaces known as splashboards, by which the splash is stayed and the ore and water directed downward onto the tables, where the values are saved on amalgam. plates, concentrator-belts, andthe like. Fur- .thermore, it is usual to employ a mortar with a rectangular ore-chamberand to use straight uncurved screens, on which much of the splash from the stamps strikes slantingwise.

My invention resides in the use of vertically-disposed or inclined transversely-corrugated amalgam-plates instead of ordinary straight non-amalgam-surface splash-boards, the object being to save as much gold as possible where a good chance is offered to save it and to prevent scouring, as would occur if a straight amalgam-surface was used. It is not customary, however, to use amalgamplates in this connection, because the sand and water would scour off all. the amalgam or silvering and leave nothing for the values to adhere to; nor, as far-as 1am aware, have horizontal amalgam-plates been used on tables, because the corrugations would leave pockets for the slowly-flowing pulp to collect in, and

the accumulated sands would cover up just that much of amalgam-surface. Amalgamplates must be subjected to as little scouring as possible. Consequently it'willbe seen how my specially-constructed splash-plate has rendered a vertically-disposed or steeply-inclined amalgam surface possible and practical. Again, I'employ a mortar having a conical ore-chamber and segmental screens, disposing the latter coaxial with, the chamber, so that all the splash from a stamp acts at right angles to the screen-surface.

Having reference to the accompanying drawings, Figure 1 is a perspective view of my stamp-mill. Fig. 2 is a central vertical section of same. Fig. 3 is a transverse sectional view of my improved splash-plate. Figs. 4, 5, 6, and 7 are modifications of same.

A represents the base-plate of a mortar to which the present invention is applied.

2 is a unitary section having the screenopenings 3 on its four sides, resting on the central annular projection 4 of the base-plate.

5 is a crown or casting seating on the central section and forming the third element of the mortar.

The three mortar-sections are suitably dovetailed at their joints to form water-tight joints and are rigidly connected together by the tiebolts 6. Ore is fed into the ore chamber through the throat 7 in the upper casting .into proximity with the stamp, (not here shown.) but which impinges in the usual manner upon the die 8. The splash from the stamp is re ceived on suitable segmental screens 9, disposed in the openings 3 concentric with the axis of the conical ore-chamber. The size mesh of the .screens depends on the desired fineness of the pulverized ore to be handled on the tables and concentrators. The interior of the ore-chamber is circular and preferably in the form of an inverted cone, and there are preferably four screen-openings, and preferably the screens are segmental, as described, because splash from the stamps takes place radially on all sides of the die, and by having the screen-surfaces substantially'at right angles to the splash the discharge is much greater than where straight screens are used and part of the splash strikes the screens 'slantingly. A one-stamp mortar of this'construction with four ten-by-eleveninch openings affords four hundred and forty square inches of screen-surface against approximately three hundred and eighty square inches for an ordinary five-stamp mortar.

The central section 2 has the peripheral longitudinal or vertical 'guide-flanges'lO adjacent each opening 3, and between each pair of these guides is fitted and removably held the splash-plates 11. These splash-plates are corrugated transversely. They are silvered or amalgamed on their inner surface and are adapted to stay the splash passing through the screens, direct the pulp and water down into the trough 12, formed on the top of the base-plate A, and to collect a portion of the As before -stated, a straight amalvalues.

gam-plate could not be used in this connection, because the amalgam or silver would quickly scour off, leaving the bare copper, which would be no better than ordinary boards. 1 have found that by using a silver plate with transverse grooves or pockets a very considerable amount of amalgam collects in the sheltered or depressed and flatter portions, the only scouring occurring on the outer exposed edges, where the water and sand run from one ledge to the other. The corrugations retard the velocity of the flow and prevent general scouring. Preferably these plates are made with rounded depressions and rather sharp attenuated ribs 13, so that a comparatively small scouring-surface is presented, with a very considerably extended protected amalgam-gathering surface. Also when a plate is in inclined position in the mortar the bottom of the depressions will be nearly flat, so as not to oifer any appreciable pockets for the accumulation of sand. By rounding the depressions the plates may be easily cleaned of their amalgam collections by suitable rubber scrapers.

The foregoing construction contemplates generally a plate with the width of the transverse depressions in excess of the distance between the lower wall of one depression and the underhanging upper wall of a succeeding lower depression. Good results are achieved particularly when the depression in crosssection approaches the segment of an oval, as in Fig. 3, where a long curved back and a rather flat bottom 1% is produced. It is obvious, however, that modifications may be made in this splash-plate without departing from the principle of a vertically-arranged amalgamed plate with transverse baflles or like means whereby the water and sand are made to flow down step by step'and the force of flow broken and whereby general scouring is prevented and there is afforded a considerable protected amalgam gathering area. Certain of these modifications are shown in Figs. 4, 5, 6, 7.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is

amalgamed surface presented toward said opening.

3. The combination with a stainp-nn'n'tar having a screened opening, of a splash-plate exterior to the opening and having its inner face presented toward said opening and amalgamed and provided with means on said face to retard the flow of water and sand thereover.

4. The combination with a stamp-mortar having a screened opening, of an amalgamcd plate exterior to the opening and in the path of material escaping therethrough said plate having depressions essentially ovoidal in crosssection.

5. The combination with a stamp-mortar having a screened opening, of an amalgamed plate exterior to the opening and capable of receiving the splash therethrough said plate having transverse depressions over which the splash flows.

6. The combination with a stamp-mortar having a screened opening, of an amalgamed splash-plate exterior to said opening and in the path of the splash therethrough, said plate having transverse depressions and attenuated partition portions between said depressions.

7. The combination with a stamp-mortar having a screened opening, of an ainalgamed splash-plate exterior to said opening and in the path of the splash thercthrough, said plate having transverse curved depressions and attenuated partition portions between said depressions.

8. The combination with a stmnp-morhw having a screened opening, of an amalgamed splash-plate exterior to said opening and in the path of the splash therethrough, said plate having transverse curved depressions and attenuated partition portions between said dopressions, the bottom of said depressions being more nearly horizontal.

9. The combination with a sectional stampmill mortar inclosing a circular crushingchamber and having a plurality of screenopenings, of segmental screens in said openings substantially coaxial with said chamber, and splash-plates exterior to the screens and in the path of the material escaping therethrough.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

GEORGE (J. RICHARDS. 

